Valve mechanism for internal combustion engines, compressors, and the like



May 17, 1938 c. D. HOWARD ET 'AL VALVE MECHANISM FOR INTERNAL COMBUSTION ENGINES, COMPRESSORS, AND THELIKE Filed Aug. l2, 1956 5 Sheets-Sheet 1 W/TIVE'SS. @QMZM.

May 17, 1938. c, D HOWARD ET A 2,117,325

VALVE MECHANISM FOR INTERNAL COMBUSTION ENGINES, COMPRESSORS, AND THE LIKE Filed Aug. 12, 1936 5 Sheets-Sheet 2 May 17, 1938. D H WA D T 2,117,325

VALVE MECHANISM FOR INTERNAL COMBUSTION ENGINES, COMPRESSORS, AND THE LIKE Fi led Aug. 12, 1936' 5 Sheets-Sheet 3 l l I y 7, 1938 c. D. HOWARD ET AL 2,117,325

VALVE MECHANISM FOR iNTERNAL COMBUSTION ENGINES, COMPRESSORS, AND THE LIKE Filed Au 12, 1936 5 Sheets-Sheei 4 v v I y 1938- c. D. HOWARD ET AL ,1

@ VALVE MECHANISM FOR INTERNAL COMBUSTION ENGINES, COMPRESSORS, AND THE LIKE Filed Aug. 12, 1936 '5 sheets sheet 5 iii J 1m w I llllll "a m w M M 'I, Q L

Patented May 17, 1938 UNITED STATES PATENT OFFICE VALVE MECHANISM FOR INTERNAL COM- BUSTION ENGINES, COMPRESSOR/S, AND

THE LIKE Application August 12, 1936, Serial No. 95,702

2 Claims.

This invention relates to an improvement in valve mechanism for internal combustion engines, compressors and the like.

Valve mechanism in accordance with this invention will be found to possess great advantage over valve mechanism, generally of the poppet type, heretofore used in internal combustion engines, compressors and the like, in that it will be positively driven, with avoidance of cams, springs, and the like, thus avoiding limitations on speed, in that it will be quiet and efilcient in operation and in that it will be safe and long lived due to the fact that its various parts may be made relatively heavy without reducing its efficiency or speed of operation.

Valve mechanism in accordance with this invention will lend itself to use with high efiiciency in connection with the control of the scavenging air in two cycle engines of the fuel injection or Diesel type, in that its use in such engines will enable their operation at higher speeds than heretofore, with consequent increase in their capacity. However, it will be understood that the mechanism in accordance with the invention will lend itself to use in Diesel engines of the four cycle type and also in internal combustion engines generally and in compressors and the like.

Having now indicated, in a general way, the nature and purpose of this invention, we will proceed to describe a preferred embodiment thereof with reference to the accompanying drawings, in which:

Figure 1 is a sectional View, partly broken away, of an engine equipped with valve mechanism in accordance with this invention.

Figure 2 is a view, partly in section and partly diagrammatic, illustrative of a cycle of operation of the valve mechanism shown in Figure 1.

Figure 3 is a sectional view showing a modification of the valve mechanism shown in Figure 1.

Figure 4 is a plan view of thesubject of Figure 3.

Figure 5 is a sectional view of a double acting engine equipped with valve mechanism in accordance with this invention.

Figure 6 is a sectional view on lines 6-6, Figure 5.

Figure 7 is a plan view, partly in section, looking in the direction of the arrow, Figure 5.

With reference to the several figures, this invention will be described as adapted to an engine of the two cycle Diesel type. However, it will be understood that, as has been indicated, it is adaptable to engines, compressors, and the like,

,of various other types.

Referring more particularly to Figures 1 and 2, I indicates an engine base on which is mounted in suitable bearings a crank shaft 2. A connecting rod 3 is secured to the crank shaft and to a piston 4 in a working cylinder 5. A suitable fuel injection device, not shown, is provided for the admission of fuel to the cylinder 5.

The working cylinder 5 is provided with exhaust ports 6, communicating with an exhaust passage I. The working cylinder is provided with cooling jackets 8.

Opening in the head of the cylinder 5, is a valve cylinder 9, provided with ports I0, afiording communication between the working cylinder 5 and a scavenging air passage I8, adapted .to be controlled by means of a slide or piston valve II.

Pivotally connectedto the piston valve II and to a rocker arm I2 on a suitably mounted fulcrum pin I3 is a link I4, while a connecting rod I5 is also connected to the rocker arm and to a crank I6 on a driven shaft [1. Shaft I1 is driven through any suitable means from the crank shaft 2.

As will be especially noted, the link I4, pivotally connected to the piston valve I I and to the rocker arm I2, forms, with the rocker arm I2, a toggle, through which the piston valve I I is reciprocated in the cylinder 9 from the driven shaft I'I, through the connecting rod I5.

The drivenshaft IT, by which the piston valve II is operated through the toggle, may be driven by any suitable form of connection from the crank shaft 2 of the engine, and will be driven, in the case of a two cycle engine, at engine speed, or, in the case of a four cycle engine, at half engine speed.

For operation of the engine above described, the rocker arm I2, when actuated by the rod I5, will be oscillated about the pin I3, thus causing the pin I9, by which the arm I2 and link I4 are connected, to move on an are between the points A and B, while the pin 20, connecting the rod I5 to the arm I2, moves on an are from the points a. to b.

Thus, when the pin 20 is in its position b, the pin I9 will be in its position B, the piston valve I I will be at the outer end of its stroke with the port I closed and the toggle, formed by the arm I2 and link I4, will be straight, or approximately straight. The mechanism will be in such position when the pressure in the cylinder is at its highest; i. e. on burning of the charge in cylinder 5, and as a consequence the heavy thrust on the piston valve II will be taken by the link I4, pin

It will be noted from an inspection of Figure 2 l9, arm l2 and pin IS, without load on the pin 20 and connecting rod l5.

From the position b the pin 20 will move toward the position a and cause the pin l 9 to move from the position B toward the position A, which results in upward travel of the piston valve II in cylinder 9. The initial movement of the piston valve; i. e. from lower dead center, at which the piston pin will be at a point E to just closing the ports l 8, at which the piston pin will be at a point F, will be very slow while the pressure on valve l I is still high and hence a low load is imposed on the pin 28 and connecting rod l5. The movement speeds up as it continues, but the pressure in cylinder 5 rapidly drops and as a consequence the loads on pin 20 and rod i5 remain low. In the continued movement of the pin 25 toward a and of the pin is toward A, the valve ports H] are opened and since the rate of movement of the pins l9 and 28 in that portion of the arcs AB and ab, in which the ports are opened, is rapid and consequently the rate of movement of the valve II from point F to point G is rapid, the ports l8 will be opened rapidly and as a consequence may be relatively large without requiring a long valve stroke.

Referring now more particularly to Figure 2, it will be noted that the toggle, as diagrammed, bends slightly with the points b, B slightly out of line when the piston valve is in lower dead center position; i. c. with the piston pin at the point E. With such arrangement little of the resistance of the toggle is lost, but the period of slow move ment of the toggle and of the piston valve is increased.

By Figure 2 the angular movement of the crank lfibetween points 0.,5' and cv and the angle of movement of crank between the points a, b, and 0', corresponding to the points a, b and c on the arc of movement of pin 28, are indicated.

that the toggle and connecting rod l are so proportioned and arranged with respect to the piston valve II that the crank [6 in rotatingthrough an arc of about 107 from c to 0' through a and in rotating in an arc of about 253 from c" to 0' through I) will cause a very slow movement of the piston valve during the period of its closure of the port and a very rapid opening and closing movement.

It will be appreciated that the movement of the piston valve ll and the subsequent opening and closing of the ports It] for the admission and cutting off of scavenging air is timed with reference to the cycle of operation of the engine. The correct timing is effected by arranging the driving connection as, for example, gears, between the crank shaft 2 and the driven shaft I! so that the rotation of the two shafts is in the proper angular relationship. In application to a four cycle engine, it will be appreciated that a pair of valves, one controlling inlet and the other exhaust, will be appropriately timed.

Referring now to Figures 3 and 4, a single working cylinder 5 may be provided with a plurality of piston valves. ll arranged in a circle about the cylinder head as indicated in Figure 4 and a plurality of the valves may be driven from a driven shaft I! through a single crank pin 2| and connecting rod l5. In such arrangement the several rocker arms l2, elements of the toggles, are provided with extensions 12', which are respectively connected to a link 22, the several fulcrum pins l3 are mounted in suitably supported bearings .24 and the connected toggles are actuated for reciprocation of the several piston valves by the connection of the connecting rod [5 to an extension 23 on one of the rocker arms l2.

The operation of the mechanism as shown in Figures 3 and 4 is as described above With reference to Figure 1.

Referring now to Figures. 5, 6 and 7, the cylinder 25 is provided with water jackets 26 and a centrally located exhaust port 21. The cylinder is provided at its opposite ends with cylinder heads 30. Within the cylinder 25 is a piston 28, to which is secured a connecting rod 29 extending through one of the cylinder heads 30 for connection with the crank shaft. The rod 29 is suitably packed, as with metal packing 3 I, to prevent leakage from the cylinder. The piston 28, in its reciprocation Within the cylinder, is adapted to partially uncover the exhaust port at opposite ends of its stroke.

The cylinder heads 30 are each provided with a pair of cylinders 32, arranged in offset relation as. shown in Figures 6 and '7; The cylinders are provided with ports 33 affording communication between the cylinders and conduits 34 for scavenging air. Within the cylinders 32 are piston valves 35 to which are pivotally connected links 36, which in turn are connected to one arm of bell cranks 3i, pivotally mounted on suitably supported pins 38.

The bell cranks connected to the pairsof piston valves in the cylinder rods, respectively, are connected by means of a link 39. Connecting rods 40 are connected to a third arm on one of the bell cranks 31, associated with the pairs of valves in the cylinder heads, respectively, and to a crank 4| on a shaft 42, driven in any suitable manner from the crank shaft of the engine.

The operation of the engine illustrated in Figures 5, 6 and 7 will, it is believed, be obvious, it being noted that for purposes of illustration the engine shown is of the double acting Diesel type. The piston valves controlling the admission of scavenging air to the cylinder 25 will be operated from the crank shaft of the engine at engine speed in the case of the engine illustratedthrough the medium of the crank shaft 42, rods 40 and the bell cranks 31 connected by links 39. It will be noted that the links 36 and the arms of the bell cranks to which they are connected will form a toggle, as do the link l4 and rocker arm I2 of the engine shown in Figure 1.

The toggles formed by the links 36 and the arms of the bell cranks 3'! to which they are connected, may be arranged as in the case of the similar mechanism shown in Figure 1 to assume a straightened out position when the piston valves are at their lower dead centers or may be arranged to break slightly backward when the piston valves are in such position, all as more fully explained with reference to Figures 1 and 2. Likewise, it will, of course, be understood that the operation of the valves will be suitably timed wit the operation of the piston 28. 7

It will be noted that the cylinders 32 in the cylinder heads 38 are arranged in offset position and also that the cylinders extend at an angle to the axis of the working cylinder 35. By virtue of such arrangement, scavenging air enters the cylinder 25 in streams traveling generally in opposite direction and also at an angle to the axis of the cylinder 25, with the result that the scavenging air is given a rotary, swirling motion in its passage to the exhaust port and operates in a highly efiicient manner to thoroughly clean burnt gases from the cylinder.

It will be understood that the above description of mechanism in accordance with this invention is for the purpose of illustration only and it will be appreciated that various modifications in detail may be made without departing from the scope of the invention.

What we claim and desire to protect by Letters Patent is:

1. In an internal combustion engine, in combination, a working cylinder, a working piston in said cylinder, a crank shaft, means connecting said working piston with said crank shaft, a passage communicating with the interior of the cylinder, a reciprocable piston valve adapted for the control of said passage, a second crank shaft, means affording a connection between said Valve and said second crank shaft including a toggle extending between and pivotally connected to said valve and a fixed pivot and a connecting rod connecting said second crank shaft with said toggle at a point adjacent to the fixed pivot, and means connecting said two crank shafts whereby said second crank shaft is rotated to effect reciprocation of said valve through said connecting rod and toggle, the toggle and said connecting rod connecting said second crank shaft with the toggle being so proportioned and arranged that in the rotation of the second crank shaft through an are of about 253 the said piston valve will move relatively slowly and so that in the rotation of the second crank shaft through an arc of about 107 the piston valve will move relatively rapidly.

2. In an internal combustion engine, in combination, a working cylinder, a working piston in said cylinder, a crank shaft, means connecting said working piston with said crank shaft, a passage communicating with the interior of the cylinder, a reciprocable valve adapted for the control of said passage, means affording a connection between said valve and said crank shaft including a toggle extending between and pivot ally connected to said valve and a fixed pivot and a connecting rod connected with said toggle at a point adjacent to the fixed pivot, and means for actuating said connecting rod to effect reciprocation of said valve through said toggle, the toggle and said connecting rod and the means for actuating said connecting rod being so proportioned and arranged that in the rotation of the crank shaft through an arc of about 253 the said valve will move relatively slowly and so that in the rotation of the crank shaft through an arc of about 107 the valve will move relatively rapidly.

CECIL D. HOWARD. FRANK R. MAXWELL. 

